I have to say, the Jelly Bean update is the worst thing they happened to my Galaxy Nexus. It is slower, the unlock screen out right locks up, the Bluetooth fails randomly; I need to reboot the phone every day to keep it usable. Lets hope that it isn't the same for other hardware...
I have this cool feature where I'm streaming pandora over bluetooth and take a call, when the caller hangs up the phone reboots. Every time. I hardly ever use my phone as an actual telephone though, so it's not a huge issue. Other than that, JB is great on my nexus.
The Xoom is also trouble free since it's update, though that device has probably the worst screen I've ever had the displeasure of looking at.
